Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2024909
CABLE REEL FOR EXPANDABLE AND CONTRACTIBLE
STEERING DEVICE OF VEHICLE
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to a cable reel in which
an electrical connection between a fixed body and a movable
body is made through a flat cable. More particularly, it
relates to a cable reel suitable for installing on an
expandable and contractible steering device of a vehicle,
the device having a telescopic function.
DESCRIPTION OF THE RELATED ART
In cable reels, one end of a plurality of turns of a
flat cable is secured to and led out of fixed bodies,
whereas the other end of the cable is secured to and led
out of movable bodies. When the movable body rotates, it
rotates through a predetermined angle by virtue of the fact
that the flat cable is caused to wind toward the side of
the movable body, or to re-wind from it. Cable reels are
installed on steering devices of automobiles in order to
serve as air bag circuits, horn circuits or cruise control
circuits (Japanese Patent Unexamined Publication No. 57-
66043).
When such a cable reel is incorporated into a steering
device, the movable body is secured to the side of a :-
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steering wheel, while the fixed body is secured to members
of the fixed side of a column cover or the like. The flat
cable led out of the fixed body is connected to a connector
on the fixed side. In a steering device equipped with a
so-called telescopic function, in which a steering wheel
can be adjusted in the axial direction of the steering
shaft, since the distance between the cable reel body and
the connector changes during the movement of the steering
wheel, a leading section which is led from the fixed body
of the flat cable must be designed long enough to allow for
the amount of the distance change.
When the leading section of the flat cable becomes
long, because it becomes an obstacle if left slack, a
storage device, for example, as disclosed in Japanese
Patent Examined Publication No. 63-32527 is required. In
such a storage device, a harness spool is provided between
the movable side and the fixed side of a steering device
with the telescopic function. At the same time, a
plurality of wire harnesses led out of the steering wheel
are housed in the harness spool while being helically
wound. The movement of the steering wheel in the axial
direction is thus absorbed by changing the radii of the
wire harnesses wound in the harness spool.
According to the above-mentioned conventional storage
device, during the telescopic operation, e.g., when the
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steering wheel is pulled toward the driver, the radii of
the wound wire harnesses change in the direction in which
they become small. On the other hand, when the steering
wheel is pushed, the radii of the wound wire harnesses
change in the direction in which they become large. Since
the radii of the wound wire harnesses can be changed within
the harness spool, long wire harnesses can be housed in a
relatively small space.
However, because the flat cable used as a lead wire of
the cable reel has a high bending rigidity and a larger
width dimension, as compared with the wire harness, when
the foregoing storage device is applied to the cable reel,
a problem occurs in that a space for housing the leading
section of the flat cable becomes excessively large. There
is also a problem in that the reliability of the connection
of the flat cable is lowered, because of an excessive
twisting force acting on the flat cable.
SUMMARY OF THE INVENTION --
In view of the aforesaid conventional art, it is an
object of the present invention to provide a highly
reliable cable reel for an expandable and contractible
steering device of a vehicle, the cable minimizing the
installation space.
To accomplish the foregoing object, the present
invention provides a cable reel for an expandable and
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contractible steering device of a vehicle, wherein the
cable reel comprises a fixed body, a movable body rotatably
attached to the fixed bod~, and a flat cable which is
housed between the fixed body and the movable body while
being wound around, both the ends of the flat cable being
electrically connected to the outsides of the fixed body
and the movable body, respectively, and wherein the cable
reel comprises a storage housing having a pair of retaining
bodies which are relatively and slidably connected to each
other, and wherein the flat cable led out of the fixed body
is affixed to the retaining bodies, respectively, being
curved in a semi-loop-like shape between these fixed
sections.
When the distance between the fixed body of the cable
reel and one of the retaining bodies of the storage housing
expands or contracts, with the shifting of the steering
wheel in the axial direction, the change in distance is
absorbed by virtue of the fact that both the retaining
bodies of the storage housing move relative to each other.
As the retaining bodies move, the shape of the flat cable
is changed while the cable is being curved within the
storage housing.
Other features will become apparent from the following
Description of the Preferred Embodiment when read with
reference to the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
All of the drawings pertain to the embodiment of the
present invention.
Fig. 1 is a front elevation view of a cable reel;
Fig. 2 is a cross-sectional view of the cable reel;
Fig. 3 is a cross-sectional view of a storage housing;
Fig. 4 is an exploded perspective view of the storage
housing;
Fig. 5 is a perspective view illustrating a movable
holder before it is assembled;
Fig. 6 is a schematic illustration of the cable reel
when it is actually installed; and
Fig. 7 is a view showing the operation of the storage
housing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will be
described hereinafter with reference to the accompanying
drawings.
Fig. 1 is a front elevation view of a cable reel
according to an embodiment of the invention. As
illustrated in Fig. 1, the cable reel includes a cable reel
body 1 and a storage housing 2.
Fig. 2 is a cross-sectional view schematically showing
the structure of the cable reel body 1. In Fig. 2, numeral
3 denotes a movable body in which a rotary cylinder 3a is
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vertically arranged at the center thereof, and a
cylindrical holder 4 is disposed outside the rotary
cylinder 3a. The holder 4 has an axially extending slit
(not shown), and is affixed to a top plate section of the
movable body 3 so as to leave a predetermined space
between the holder 4 and the periphery of the rotary
cylinder 3a. Numeral 5 denotes a flat cable where a
plurality of conductors are laminated by a pair of flexible
films made of polyethylene terephthalate or the like. The
flat cable 5 is wound around a plurality of times. The
leading portion of the wound flat cable 5 is re-wound
inside the holder 4 after having passed through the slit,
and is led out of the movable body 3. An unillustrated
connector is connected to the end of a leading section 6 on
the movable side of the movable body 3.
Numeral 7 designates a fixed body. A center hole 7a
in which the rotary cylinder 3a of the above movable body 3
snaps is formed at the center of the fixed body 7. An
outer ring wall 7b, regulating the re-winding position of
the above-mentioned flat cable 5, is vertically arranged on
the periphery edge of the fixed body 7. Further, a ring
member 8 is attached to the top end of the outer ring wall
7b, and the movable body 3 is caused to slidably rotate
along the ring member 8. Furthermore, guide sections 7c,
8a are formed, so as to protrude diagonally downward, in
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parts of the fixed body 7 and the ring member 8. The end
of the wound portion of the flat cable 5 is re-wound in$ide
the outer ring wall 7b, and then is led out of the fixed
body 7, after having passed through the guide sections 7c,
8a. A leading section 9 on the fixed side of the guide --
sections 7c, 8a leads to the above storage housing 2.
The storage housing 2 will now be described in detail
with reference to Figs. 3 through 5.
Fig. 3 is a cross-sectional view of the storage
housing 2; Fig. 4 is an exploded perspective view of the
storage housing 2; and Fig. 5 is a perspective view
illustrating a movable holder with which the storage
housing 2 is equipped. In these drawings, numeral 10
indicates a movable holder, while 11 indicates a fixed
holder. Both of the holders 10, 11 are slidably connected
to each other and constitute the storage housing 2.
The movable holder 10 has a pair of side plates 12.
Two cylindrical struts 13, 14 and one track-shaped guide
post 15 are installed between the two side plates 12.
Further, projections 12a are formed on the outer surfaces
of the side plates 12. As illustrated in Fig. 5, a block
body including the pair of side plates 12 consists of an
integrally molded item which is connected to the pair of
side plates 12 through a thin-walled hinge 16. As shown in
Fig. 4, the movable holder 10 in which one side plate 12
202~go9
faces the other side plate 12 is formed by bending, along
the hinge 16, one side plate 12 toward the other side plate
12 by an angle of 180, before the movable holder 10 is
screwed. In other words, the movable holder 10 is formed
by bending, along a dash-and-two-dot line or bending line,
one side plate 12 toward the other side plate 12 in a
direction indicated by an arrow. The movable holder 10
further has a strip-like leg 17, and track-shaped attaching
holes 18 are formed in both ends of the strip-like leg 17.
The above-mentioned fixed holder 11 is made up of a
substrate 19 and a cover 20, both of which are integrally
joined to each other by means of a plurality of screws. A
leg 22 having a track-shaped attaching hole 21 is provided
on the outer face of the substrate 19 and on the outer face
of the cover 20. Furthermore, longitudinally extending
guide grooves 23 are formed on the inner face of the
substrate 19 and on the inner face of the cover 20 (the
guide groove on the side of the cover 20 is not shown).
The above projections 12a of the movable body 10 are
engaged with the guide grooves 23 so as to travel back and
forth along the guide grooves 23.
A partition 24 forming a cave-like space and a guide
wall 25 located in the cave-like space are provided on one
side along the longitudinal direction of the above-
mentioned substrate 19. Further, a semi-cylindrical
2024909
expanding wall 26 and a regulating wall 27 opposite to the
expanding wall 26 are provided on the other side of the
substrate 19. A cable discharging path 28 is partitioned
between the expanding wall 26 and the regulating wall 27.
Also, a guide rod 29 is provided inside the substrate 19.
The foregoing partition 24, guide wall 25, expanding wall
26, regulating wall 27, and the guide rod 29 extend so as
to form a bridge from the side plate of the substrate 19 to
the cover 20.
The foregoing leading section 9 on the fixed side of
the guide sections 7c, 8a which is led out of the fixed
body 7 of the cable reel body 1 is casued to lead to the
inside of the partition 24 while being curved in a semi-
loop shape, after the leading section 9 is affixed to the
movable holder 10 while being curved in an S shape along
the peripheral faces of the one of the struts 13 and of the
guide post 15 of the movable holder 10. The leading
section 9 is further made to be affixed to the fixed holder
11, after having been turned the other way along the guide
wall 25, and then to lead out of the fixed holder 11, after
having passed, while being guided by the guide rod 29,
through the cable discharging path 28 between the expanding
wall 26 and the regulating wall 27. Further, protective
tapes 30 made of vinyl chloride resin or the like are stuck
to the leading section of the fixed holder 11 and part of
202~909
the flat cable 9 between the cable reel body 1 and the
movable holder 10. Furthermore, a curved section 9a of the
flat cable 9, leading from the fixed holder 10 to the fixed
section of the fixed holder 11, is clamped together by a
pair of supporting plates 31 made of a flexible film. Both
ends of these supporting plates 31 are attached to the
stages of the guide post 15, the partition 24, the guide
wall 25, and the like to prevent the flat cable 9 from
coming off.
Fig. 6 is a schematic illustration of the cable reel
constructed as described above when the cable reel is
actually installed on an expandable and contractible
steering device with a telescopic function. In Fig. 6,
numeral 32 denotes a steering wheel; 33 denotes a column;
and 34 denotes a telescopic function. The movable body 3
of the cable reel body 1 is secured to the side of the
steering wheel 32, and the fixed body 7 is secured to the
side of the movable stage of the telescopic function 34.
The leg 17 of the movable holder 10 in the storage housing
2 is secured to the movable stage side of the telescopic
function 34, and the leg 22 of the fixed holder 11 is
secured to the members on the fixed side of the column 33
and the like. The steering wheel 32, the cable reel body 1
and the movable holder 10 of the storage housing 2 are made
to shift by the telescopic function 34 in axial directions --
--10--
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of an unillustrated steering shaft (in directions indicated
by arrows A and B).
Under such conditions where the cable reel body 1 is
actually installed, rotating the steering wheel 32 in one
direction causes the flat cable 5 in the cab'Le reel body 1
to be wound toward the holder 4 of the movable body 3,
while on the contrary, rotating the steering wheel 32 in
the other direction causes the flat cable 5 to be re-wound
to the side of the outer ring wall 7b of the fixed body 7.
In either case, an electrical connection between the
steering wheel 32 and the cable reel body 1 is maintained
by the leading section 6 on the'movable side of the flat
cable 5; an electrical connection between the movable body
3 and the fixed body 7 of the cable reel body 1 is
maintained by the flat cable 5; and an electrical
connection between the cable reel body 1 and the members on
the fixed side of the column 33 and the like is maintained
through the leading section 9 on the fixed side of the flat
cable 5.
Fig. 7 is a view showing the operation of the storage
housing 2 and corresponds to the state where the steering
wheel 32 is pulled in the direction indicated by'the arrow
B (a position indicated by broken lines) of Fig. 6. In
this case, the movable holder 10 and the fixed holder 11
are in the state where they are expanded to the fullest
2024909
extent. The curved section 9a of the flat cable 9 is
positioned where it is indicated by-a solid line.
On the contrary, when the steering wheel 32 is pushed
in the direction indicated by the arrow A of Fig. 6, the
cable reel body 1 and the movable holder 10 shift in the
same direction as that of the steering wheel 32, as the
steering wheel 32 moves. The movable holder 10 descends
inside the fixed holder 11 by virtue of the fact that the
projections 12a slide in the guide grooves 23. Due to the
above, the distance between the movable body 10 and the
fixed holder 11 is made the shortest, and this change in
distance is absorbed by the shifting of the curved section
9a of the flat cable 9 as indicated by dash-and-two-dot
lines of Fig. 7.
Thus, in the above-described embodiment, since the
axial shift of the steering wheel 32 during the telescopic
operation is absorbed by the shifting, within the storage
housing 2, of the curved section 9a of the flat cable 9, it
is possible to arrange the leading section 9 of the flat
cable 5 in a small space, the leading section 9 being
required between the cable reel body 1 and an external
connector.
Further, the supporting plates 31 overlapped at the
curved section 9a of the flat cable 9 prevent the curved
section 9a from being bent, thereby improving the
-12-
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reliability of the cable reel.
Furthermore, because the movable holder 10 is an
integrally molded item which is connected to the pair of
side plates 12 through the hinge i6, it is possible to
reduce the number of required parts.
In addition, it is possible to absorb to some extent
errors in dimensions of the various parts, since the flat
cable 9 is capable of shifting between the struts 13, 14
within the movable holder 10, and since the attaching holes
18 of the movable holder 10 and the attaching holes 21 of
the fixed holder 11 are shaped like long, slender tracks in
directions perpendicular to the shifting direction of the
flat cable 9.
As has been described above, according to the present
invention, even when the distance between the cable reel
body and the external connector changes during the
telescopic operation or the like, it is possible to house
the above leading section of the flat cable in a small
space without slacking it, the leading section being
required between the cable reel body and the external
connector. This is because the flat cable led out of the
fixed body is affixed to a pair of retaining bodies which
are relatively and slidably connected to each other, and
because a semi-loop-like curvèd section is formed between
the pair of retaining bodies. The value of the practical
2024sns
use of the cable reel is thus enhanced.
As many widely different embodiments of the present
invention can be made without departing from the spirit and
scope thereof, it is to be understood that the invention is
not limited to the specific embodiment thereof except as
defined in the appended claims.
